Fig. 1
Constant light for 5 weeks disrupts circadian rhythms in general activity and core body temperature (Tb). (a) Representative double-plotted actograms from LD and (b) LL rats respectively. Black and white horizontal bars on top of the actograms represent night and day. The change in the lighting condition after 12 days of baseline (12:12 h LD cycle) is indicated with the legend “lights on” and the large white bar representing the constant light condition. (c) The χ2 periodogram test for the last 14 days demonstrates a 24 h rhythm for LD and (d) the absence of a circadian rhythm for LL rats. (e) Mean temperature values from the last 2 days of the lighting schedule for LD (grey circles) and LL (white circles) rats along 24 h. (f) Mean day-night temperature values for LD (grey bars) and LL (white bars), stripped bars in each group represent the night. Data are the mean ± SEM (n = 8/group). For E the repeated-measures two-way ANOVA, indicated significant interaction of the lighting condition versus time p < 0.0001. For F the two-way ANOVA indicated significant interaction of the lighting condition versus time p < 0.0001. The Bonferroni test indicated statistical difference LL from LD *p < 0.05 for F and indicated & p < 0.001 between day and night in the LD group